Text help!

Right,my name is Aryan and I'm new to this community so first of all hello people.I'm having some problems with my text at the moment and I hope you all can help me out.I use Photoshop CS and few days ago my text was working just fine but today when I clicked the Text tool and tried to type something......I couldnt! There was just a small square.I did many things like increase the size,change fonts,tried later,etc but nothing worked.Whenever I click the text tool a small black square comes up.I typed something really random and after some time there was just a line instead of the text.I don't remember messing around with the text settings to cause this problem.I hope you all can understand what I'm trying to say and and help me!

Thanks in advance
Aryan